RRBO has closed, but I am still working on several RRBO-related projects, as well as continuing to do urban ecology research independently and providing expertise and service to the scientific community. So whether you are interested in Dearborn and southeast Michigan birds; urban ecology with a focus on birds, insects, and plants in the Midwest; and/or similar endeavors, I hope you continue to follow along here!
Here are some updates:
First, I was asked to work on helping finish a really interesting bird conservation project by the U.S. Fish and Wildlife Service. My involvement was just about squared away when the government shutdown occurred. While I'm pretty sure the project will be completed one day, I have no idea when or how this will happen until after the government reopens, the people involved catch up on their work, and how their budgets shake out.
Meanwhile, I am in the process of bringing the Dearborn bird checklist up to date. There have
been some taxonomy changes, and I will move any material from the RRBO
website on rare or interesting birds here to Net Results, link to
those items on the checklist, and publish it here. I've also been working on a substantially revised annotated checklist. More on that soon.
In April 2019, hosting for the RRBO website will be up for renewal. I pay for this hosting myself, and therefore I'm going to let it lapse. At that time, the RRBO website will be no more, and the URL will point here. I have been and will be moving some material over here to the blog, including the entire section on European cage birds that have become established in the western Great Lakes. This is research I'm continuing, and I plan on publishing another paper. I'll be posting this section shortly.
Recently, a new paper came out that drew upon data I provided. "Species interactions limit the occurrence of urban-adapted birds in cities" was published in the journal PNAS (Proceedings of the National Academy of Sciences of the United States). You can read a news story about it here. I have always strongly believed in sharing data, so even when I have not had the chance to use it in my own publications, I've been happy to contribute to the projects of others.
Finally, I also still post pretty regularly to the RRBO Facebook page, so feel free to engage there.
Thursday, January 24, 2019
Friday, August 31, 2018
RRBO is closing
Due to a lack of sustainable funding, the Rouge River Bird Observatory will cease operations in October 2018. I will be leaving the University as a retiree with Visiting Scholar status, and hope to finish publishing RRBO-related research. I will continue to maintain this blog, and social media (Facebook) for the time being, and I'll use these venues to post updates on publications and related news, for those interested.
I will still be collecting data on European Goldfinches! Please see this page on how to submit data.
Finally, I sincerely thank everyone who supported RRBO in so many ways the past 26 years.
--- Julie Craves
I will still be collecting data on European Goldfinches! Please see this page on how to submit data.
Finally, I sincerely thank everyone who supported RRBO in so many ways the past 26 years.
--- Julie Craves
Thursday, September 7, 2017
New major paper published
This paper describes the interactions between native birds, a specialist moth, and the moth’s new host in North America, Amur honeysuckle, a problematic non-native shrub.
On a bird survey in late fall 2015, I came across a small flock of chickadees that appeared to be finding food on the leaves of Amur honeysuckle along the Rouge River. This non-native shrub dominates the forest understory in this area, as it does over a large swath of North America east of the Great Plains. The feeding behavior was very interesting to me, as Amur honeysuckle is known to be largely free of insect herbivores, even more so than the other species of non-native honeysuckles that are so common in urban forests.
A closer look revealed that nearly every Amur honeysuckle had leaves that were heavily infested with leaf mines, and that the chickadees were opening these mines and feeding on the insects within them. This was even more intriguing! Because they live and feed within plant tissues, leaf mining insects tend to be very host-specific, and specialized insects like this were supposed to be especially rare on most introduced plants, Amur honeysuckle included.
I reared the tiny caterpillars, overwintered them, and had the emerging insects (which were moths) identified by DNA barcoding in 2016. I continued my observations on bird use of the moth larvae, the extent of the infestation, and population status in 2016. My paper details these findings, which are novel in several ways:
- This is the first record of this moth species, or any in the same moth family of over 2000 species, using Amur honeysuckle as a host in North America
- The native ranges of the moth and the shrub do not overlap, indicating evolutionary adaptation was involved in the host switch
- Some of the bird species using the moth larvae have never been documented feeding on leaf mining moths
- Because Amur honeysuckles holds leaves (with occupied mines) until well after killing frost, these larvae supply protein to birds at a time when other insects have become scarce
This link will take you to the abstract of the paper. If you'd like to read the full paper, please contact me by using the form in the footer.
Many other papers can be downloaded at my Researchgate profile.
Saturday, July 1, 2017
Odd plumages and abnormal feather growth
Birds with abberant plumage are one of the more common oddities we see at the Rouge River Bird Observatory. Abnormally-colored feathers are fairly frequent, and some examples are below. One example has its own page: a stunning white-breasted American Robin.
Once or twice a year, we see an American Robin (Turdus migratorius) that has several white feathers or patches of white feathers. This one was photographed by Darrin O'Brien on 29 Apr 2009 at a Dearborn office complex.
This unusual American Robin was banded on 7 Oct 2007. It was an adult female undergoing its fall molt. The breast feathers were normal. However, nearly all of the incoming feathers on the wings, tail, and body that are gray in normal robins were full or partially "frosty" looking.
Typically when abnormal white feathers are seen on birds, the entire feather is white, as in the first example. Partially white feathers like this are something RRBO encounters only rarely, and not to the extent found on this bird.
The bird was re-sighted the following week.
A leucistic Yellow-rumped "Myrtle" Warbler (Dendroica coronata) was found at the on campus from 15 to 17 May 1997. The wings and tail of this bird were entirely white. Soft yellow was visible where most yellow-rumps have bold yellow on the flanks. The back and head were pale gray, and some pale gray streaking replaced the prominent streaking of normal-plumaged yellow-rumps. This bird appeared to be a male. While relatively common in some families of birds, abnormally pigmented individuals are rare in the Parulidae (wood warblers).
This sighting was documented in the following paper:
Craves, J. A. 1997. Extreme leucism in a Yellow-rumped Warbler (Dendroica coronata coronata). Michigan Birds and Natural History 4:199-200.
Carotenoids are the pigments responsible for most of the red and yellow colors in birds. They cannot be created by birds without dietary input. Thus, the pigments in what birds eat can influence the color of their feathers. If a bird consumes particular deep red pigments while feathers are in active growth and also has yellow plumage, some or all of the yellow feathers may turn out to be orange. This is most frequently seen in the terminal tail bands of Cedar Waxwings (Bombycilla cedrorum), which are normally yellow. About 5% of the Cedar Waxwings banded by RRBO have had orange terminal tail bands (right). It was first noticed in the 1960s, and it has since been confirmed that it is due to waxwings consuming the fruit of introduced Morrow's Honeysuckle (Lonicera morrowii), which contains a red pigment called rhodoxanthin. This honeysuckle is common at UM-Dearborn.
A number of other bird species have been recorded with orange or reddish feathers in place of yellow feathers that could be attributable to ingestion of rhodoxanthin. The White-throated Sparrow (Zonotrichia albicollis) at right was banded by RRBO on 27
September 1998. This bird has orange-colored lores rather than yellow.
Subsequently, RRBO has banded two more White-throated Sparrows with
orange lores, and this phenomena has also been reported by other
banders.
The first record was documented in the following paper:
Craves, J. A. 1999. White-throated Sparrow with orange lores. Michigan Birds and Natural History 6:83-84.
Further reading:
Tricks Exotic Shrubs Do: When Baltimore Orioles Stop Being Orange (pdf) by Tom Flinn, Jocelyn Hudon, and Dan Derbyshire -- article from Birding magazine.
Diet explains red flight feathers in Yellow-shafted Flickers in eastern North America. Hudon, J., R.J. Driver, N.H. Rice, T.L. Lloyd-Evans, J.A. Craves, and D.P. Shustak. 2017. The Auk: Ornithological Advances 134:22-33.
Occasionally we have encountered Northern Cardinals (Cardinalis cardinalis) that are very vividly colored or with some orange plumage. The male on the right was banded by RRBO on 25 October 2000. It had patches of orange feathers, and several wing feathers that were orange. This abnormality may have been caused by a lack of some sort of dietary pigment that left the normally red feathers less intensely red. Dietary deficiency of certain carotenoids is responsible for orange- or yellow-colored House Finches (Carpodacus mexicanus).
Perhaps some lack in the diet combined with ingestion of a red pigment like rhodoxanthin that contributed to the orange color as well as the crimson color of the red plumage. Other orange cardinals have turned up in the literature and on the
Internet, beginning in the late 1990s, lending some credence to the role
of honeysuckles and rhodoxanthin in this plumage variation.
Further reading:
An 'orange variant' Northern Cardinal. (pdf) Hansrote, C. and M. 2000. North American Bird Bander 25:1-3.
And now, a white/pink cardinal! Ohio Birds and Biodiversity.
The yellow cardinal lives on. Ohio Birds and Biodiversity.
RRBO has banded a half-dozen Ruby-crowned Kinglets (Regulus calendula) with at least some orange crown feathers rather than salmon red, all since the year 2000. Examples of two individuals are shown below. This may also be due to a dietary deficiency.
The first secondary feather on one wing of this American Goldfinch (Spinus tristus), banded 20 Aug 2010 was completely black on the underside, rather than having a white base. When melanism occurs, it seems that it typically affects all feathers. RRBO has not documented a single melanistic feather or patches of melanistic feathers on any birds, much less the thousands of goldfinches banded on campus.
More information on abnormal plumage coloration
Davis, J. N. 2007. Color abnormalities in birds: A proposed nomenclature for birders. Birding 39:36–46.
David Sibley's web site: Abnormal coloration in birds: Melanin reduction.
British Trust for Ornithology's Abnormal Plumage Survey page.
The first was a young House Wren (Troglodytes aedon) banded on 1 Oct 2003. The tips of 5 tail feathers (rectrices, or “rects”) had unusual, spatulate tips which extended about 5 mm past the “normal” ends of the feathers.
The extensions did not appear to be formed by the wearing away of some of the feather barbs. This was the first time RRBO had ever seen a bird with a tail like this.
On 25 Aug 2008, a young Carolina Wren (Thryothorus ludovicianus) was captured that had a similar tail. This bird only had the odd paddle-like extension on the central tail feather. We recaptured this bird several times that season, and this feather was present each time.
On 5 October 2008, we banded a White-throated Sparrow (Zonotrichia albicollis). One central tail feather was around 10 mm longer than the other feathers. All the rects were fully grown in, so it wasn’t a case of the other feathers having not reached their full length.
Finally, there was the recent capture of a similar case. This adult Cedar Waxwing (Bombycilla cedrorum) also had two extra-long central tail feathers. As with the White-throated Sparrow above, all the feathers were fully grown. It was banded on 8 November 2011.
Plumage that is abnormally white
An an abnormal reduction in the deposition of pigment in the feathers is known as leucism. Some leucistic birds appear entirely washed out or pale if the reduction of pigment is roughly equal in all feathers (some authors now call this “hypomelanism”). More often, pigment is absent in only some feathers, and this is known as pied leucism, or “partial amelanism.” Causes include genetics, or injury, disease, or malnutrition.This unusual American Robin was banded on 7 Oct 2007. It was an adult female undergoing its fall molt. The breast feathers were normal. However, nearly all of the incoming feathers on the wings, tail, and body that are gray in normal robins were full or partially "frosty" looking.
Typically when abnormal white feathers are seen on birds, the entire feather is white, as in the first example. Partially white feathers like this are something RRBO encounters only rarely, and not to the extent found on this bird.
The bird was re-sighted the following week.Plumage that is abnormally orange
Further reading:
Tricks Exotic Shrubs Do: When Baltimore Orioles Stop Being Orange (pdf) by Tom Flinn, Jocelyn Hudon, and Dan Derbyshire -- article from Birding magazine.
Diet explains red flight feathers in Yellow-shafted Flickers in eastern North America. Hudon, J., R.J. Driver, N.H. Rice, T.L. Lloyd-Evans, J.A. Craves, and D.P. Shustak. 2017. The Auk: Ornithological Advances 134:22-33.
Further reading: An 'orange variant' Northern Cardinal. (pdf) Hansrote, C. and M. 2000. North American Bird Bander 25:1-3.
And now, a white/pink cardinal! Ohio Birds and Biodiversity.
The yellow cardinal lives on. Ohio Birds and Biodiversity.
RRBO has banded a half-dozen Ruby-crowned Kinglets (Regulus calendula) with at least some orange crown feathers rather than salmon red, all since the year 2000. Examples of two individuals are shown below. This may also be due to a dietary deficiency.
Abnormally dark plumage
When birds have plumage with excess pigment, usually the dark melanin pigments, they are known as melanistic. This Mourning Dove (Zenaida macroura) was seen in the Dearborn yard of Julie Craves and Darrin O'Brien on 8 Apr 2006. The second photo shows it compared to a normally-colored Mourning Dove.
The first secondary feather on one wing of this American Goldfinch (Spinus tristus), banded 20 Aug 2010 was completely black on the underside, rather than having a white base. When melanism occurs, it seems that it typically affects all feathers. RRBO has not documented a single melanistic feather or patches of melanistic feathers on any birds, much less the thousands of goldfinches banded on campus.
More information on abnormal plumage coloration
Davis, J. N. 2007. Color abnormalities in birds: A proposed nomenclature for birders. Birding 39:36–46.
David Sibley's web site: Abnormal coloration in birds: Melanin reduction.
British Trust for Ornithology's Abnormal Plumage Survey page.
Abnormal feather growth
On several occasions, the Rouge River Bird Observatory has banded a bird that had an unusual tail.
See more weird birds:
- Strange looking birds -- Cornell's Project FeederWatch
- Atypical birds photo gallery at BirdWatching Magazine
- Miscolored birds Flickr photo pool (no longer moderated, so not all birds are valid examples)
Friday, April 21, 2017
Winter Bird Population Survey 2016-2017
The 25th year of RRBO's Winter Bird Population Survey was completed in February.
It was another mild winter. It began rather snowy with temperatures close to average, but January and February saw less snow and temperatures well above normal. Surveys were conducted on 16 days (previous mean 14) with 26.5 hours total (mean is 27.7). For the third year, I was unable to survey anywhere along the Rouge River from Fair Lane Estate south due to it being fenced off for riverbank restoration.
A total of 41 species was two above the previous 24-year mean. Two new species for the survey were recorded: Field Sparrow and the female Pileated Woodpecker that has been present on campus since fall. These bring the cumulative total for the survey to 79 species.
Fruit-eating birds were scarce again. Robins were in low numbers. No Hermit Thrushes, Cedar Waxwings, or Yellow-rumped Warblers were recorded. These latter 3 species have become more and more scarce the last 5 or so years. Because they typically occur in fairly low numbers, I have not yet worked with their data. But the trends with robins might shed some light (see below).
Now that we are at the 25 year mark, I thought I would provide a little summary data and analysis.
Twenty species have been found every year: Canada Goose, Mallard, Red-tailed Hawk, Mourning Dove, Red-bellied Woodpecker, Downy Woodpecker, Hairy Woodpecker, Blue Jay, American Crow, Black-capped Chickadee, White-breasted Nuthatch, Brown Creeper, American Robin, European Starling, American Tree Sparrow, Dark-eyed Junco, Northern Cardinal, House Finch, American Goldfinch, and House Sparrow. Five more were found on 24 counts: Cooper's Hawk, Ring-billed Gull, Tufted Titmouse, Carolina Wren, and Song Sparrow. These 25 species can be considered our core winter residents.
About a third of the species have only been recorded one or two years, and can be considered rarities in winter. Some of the more interesting ones include Northern Shrike (winter 1995-96), Long-eared Owl (2009-10), Rough-legged Hawk (1994-95), and White-winged Crossbill (2008-09).
Population trends take a little more time to work through, so I just did some quick calculations on common species to see if anything popped out. Not much obvious was apparent for most species using the limited analysis* performed. Perhaps the most interesting were the trends for the two most abundant fruit eaters, American Robin and European Starling.
Both species for many years were more or less stable, with increases starting around ten years ago. I suspect this would correlate with increasing average winter temperatures and decreasing snow cover, but I have not yet incorporated weather data into my analyses. Around 2010 (vertical line on graph) both species being to show declines. This was approximately the time when large-scale removal of invasive fruiting tree and shrubs began, which both bird species heavily utilize in winter. This may indicate a pitfall of removing an important food source without concurrent restoration. Indeed, an examination of robin fecal samples from 2009 through 2017 shows a 52% decrease in the proportion of samples containing non-native Common Buckthorn (Rhamnus cathartica) seeds, the first primary target of the eradication effort. A closer look at the fecal samples reveals another unfortunate result of removing a food source without replacing it with something more desirable.
Non-native Callery or Bradford Pear (Pyrus calleryana) and Border Privet (Ligustrum obtusifolium) have become naturalized on campus. Their seeds did not appear in fecal samples until 2013, but have been increasing every year since. These species are generally not favored by birds -- pear fruits are fairly large and mealy, while privets are dry and have large seeds and little pulp. These percentages are modest, but bear in mind that the vast majority of plant species are found in less than 3% of samples; samples are dominated by buckthorn, non-native crabapples, and non-native honeysuckles. The third species in the chart is non-native Oriental Bittersweet (Celastrus orbiculatus). While there is some native American Bittersweet (Celastrus scandens) here, Oriental Bittersweet is far more common. Birds seem to favor Oriental Bittersweet, perhaps because it has slightly smaller fruit and smaller seeds. Seeds of bittersweet have have greatly increased. Robins, at least, appear to be turning to alternative fruits, those that are less desirable or not as common as what has been removed. This creates an undesirable feedback loop: increased consumption will also lead to increased dispersal of these species.
One other bird species appeared to respond to the habitat changes that started in 2010.
Mourning Doves may be increasing due to the substantial clearing of the understory.
Over the past 25 years, two other events had an influence on bird population. One was the arrival of West Nile Virus in 2001 (vertical line in graph below). I have shown the dramatic decline in American Crows before, and they have yet to recover.
Blue Jays are related and also known to have been impacted by the virus. Their populations appear to have rebounded nicely.
Finally, the Emerald Ash Borer was detected here around 2002, and all our ash trees died within a few years.
While the modest increases might be due to extra food for woodpeckers in dead and dying trees, I don't think the data here indicate that the beetles had much of an effect on woodpecker populations. It might be due to methodology, but since "housing" is often the limiting factor for cavity nesters and the ash trees tended to fall over shortly after death and therefore did not supply more cavities, I think the overall impact on woodpecker numbers was modest.
*Notes on methods: I looked at species seen every year that had an average of 5 or more individuals seen per survey day; I excluded waterfowl and added American Crow and Red-bellied Woodpecker. I used birds per survey day rather than raw numbers or hours because for most species that provided the strongest correlation. To smooth out data I used a 3-year moving average, which is why the graphs begin in 1996 rather than 1993. When I work on a full analysis, I will be more thorough and provide more details on methods, but for the purposes of this post, these methods should suffice.
It was another mild winter. It began rather snowy with temperatures close to average, but January and February saw less snow and temperatures well above normal. Surveys were conducted on 16 days (previous mean 14) with 26.5 hours total (mean is 27.7). For the third year, I was unable to survey anywhere along the Rouge River from Fair Lane Estate south due to it being fenced off for riverbank restoration.
A total of 41 species was two above the previous 24-year mean. Two new species for the survey were recorded: Field Sparrow and the female Pileated Woodpecker that has been present on campus since fall. These bring the cumulative total for the survey to 79 species.
Fruit-eating birds were scarce again. Robins were in low numbers. No Hermit Thrushes, Cedar Waxwings, or Yellow-rumped Warblers were recorded. These latter 3 species have become more and more scarce the last 5 or so years. Because they typically occur in fairly low numbers, I have not yet worked with their data. But the trends with robins might shed some light (see below).
Now that we are at the 25 year mark, I thought I would provide a little summary data and analysis.
Twenty species have been found every year: Canada Goose, Mallard, Red-tailed Hawk, Mourning Dove, Red-bellied Woodpecker, Downy Woodpecker, Hairy Woodpecker, Blue Jay, American Crow, Black-capped Chickadee, White-breasted Nuthatch, Brown Creeper, American Robin, European Starling, American Tree Sparrow, Dark-eyed Junco, Northern Cardinal, House Finch, American Goldfinch, and House Sparrow. Five more were found on 24 counts: Cooper's Hawk, Ring-billed Gull, Tufted Titmouse, Carolina Wren, and Song Sparrow. These 25 species can be considered our core winter residents.
About a third of the species have only been recorded one or two years, and can be considered rarities in winter. Some of the more interesting ones include Northern Shrike (winter 1995-96), Long-eared Owl (2009-10), Rough-legged Hawk (1994-95), and White-winged Crossbill (2008-09).
Population trends take a little more time to work through, so I just did some quick calculations on common species to see if anything popped out. Not much obvious was apparent for most species using the limited analysis* performed. Perhaps the most interesting were the trends for the two most abundant fruit eaters, American Robin and European Starling.
Both species for many years were more or less stable, with increases starting around ten years ago. I suspect this would correlate with increasing average winter temperatures and decreasing snow cover, but I have not yet incorporated weather data into my analyses. Around 2010 (vertical line on graph) both species being to show declines. This was approximately the time when large-scale removal of invasive fruiting tree and shrubs began, which both bird species heavily utilize in winter. This may indicate a pitfall of removing an important food source without concurrent restoration. Indeed, an examination of robin fecal samples from 2009 through 2017 shows a 52% decrease in the proportion of samples containing non-native Common Buckthorn (Rhamnus cathartica) seeds, the first primary target of the eradication effort. A closer look at the fecal samples reveals another unfortunate result of removing a food source without replacing it with something more desirable.
Non-native Callery or Bradford Pear (Pyrus calleryana) and Border Privet (Ligustrum obtusifolium) have become naturalized on campus. Their seeds did not appear in fecal samples until 2013, but have been increasing every year since. These species are generally not favored by birds -- pear fruits are fairly large and mealy, while privets are dry and have large seeds and little pulp. These percentages are modest, but bear in mind that the vast majority of plant species are found in less than 3% of samples; samples are dominated by buckthorn, non-native crabapples, and non-native honeysuckles. The third species in the chart is non-native Oriental Bittersweet (Celastrus orbiculatus). While there is some native American Bittersweet (Celastrus scandens) here, Oriental Bittersweet is far more common. Birds seem to favor Oriental Bittersweet, perhaps because it has slightly smaller fruit and smaller seeds. Seeds of bittersweet have have greatly increased. Robins, at least, appear to be turning to alternative fruits, those that are less desirable or not as common as what has been removed. This creates an undesirable feedback loop: increased consumption will also lead to increased dispersal of these species.
One other bird species appeared to respond to the habitat changes that started in 2010.
Mourning Doves may be increasing due to the substantial clearing of the understory.
Over the past 25 years, two other events had an influence on bird population. One was the arrival of West Nile Virus in 2001 (vertical line in graph below). I have shown the dramatic decline in American Crows before, and they have yet to recover.
Blue Jays are related and also known to have been impacted by the virus. Their populations appear to have rebounded nicely.
Finally, the Emerald Ash Borer was detected here around 2002, and all our ash trees died within a few years.
While the modest increases might be due to extra food for woodpeckers in dead and dying trees, I don't think the data here indicate that the beetles had much of an effect on woodpecker populations. It might be due to methodology, but since "housing" is often the limiting factor for cavity nesters and the ash trees tended to fall over shortly after death and therefore did not supply more cavities, I think the overall impact on woodpecker numbers was modest.
*Notes on methods: I looked at species seen every year that had an average of 5 or more individuals seen per survey day; I excluded waterfowl and added American Crow and Red-bellied Woodpecker. I used birds per survey day rather than raw numbers or hours because for most species that provided the strongest correlation. To smooth out data I used a 3-year moving average, which is why the graphs begin in 1996 rather than 1993. When I work on a full analysis, I will be more thorough and provide more details on methods, but for the purposes of this post, these methods should suffice.
Thursday, March 23, 2017
The forgotten Detroit River Ivory Gull
As far as I know, the first documented Ivory Gull in Michigan was an immature bird seen on the Detroit River between Grosse Ile and Trenton on 12 January 1949. This short note was published in Michigan Audubon's The Jack-Pine Warbler (Vol. 27, No. 2) in 1949.
A little more on these observers: Laurel (not Lauren) Van Camp was a game warden for Ottawa County, Ohio (later with the Ohio Department of Natural Resources), a prolific conservation writer and bird bander, and the man who laid out the trails at what is now the Magee Marsh Bird Trail (read more in this piece from the Black Swamp Bird Observatory). Morgan Wilson and Fred Brint were both with the U.S. Fish and Wildlife Service and worked in game management and Migratory Bird Treaty enforcement. John Anderson was a waterfowl and wildlife biologist and manager of the Winous Point Shooting Club in Port Clinton, Ohio. These were all professional biologists that specialized in waterfowl and thus also likely to be well-versed in gulls and other waterbirds.
At that time (of landline telephones and bulky, expensive film cameras) there was no formal avenue or protocol to report interesting birds. A regular record of birds was published in the Jack-Pine Warbler in its seasonal survey, and more compelling birds were written up and published, as above.
Nearly 40 years later, an organization of birders was formed to maintain the official state bird checklist, including by determining the acceptability of sightings of birds unusual to the state. Soon after its formation in 1988, the Michigan Bird Records Committee began reviewing historical records. Initially, all first state records had to be accepted by a unanimous vote. The Detroit River Ivory Gull was "not accepted" due to a 6-1 vote; the write up from the 1990-91 annual report is below:
In 1999, the Committee rules changed, and first state records could be accepted under same standards as other records (a vote of 7-0 or 6-1 in the first round of voting, or 5-2 or 4-3 in a resubmitted round). The Detroit River Ivory Gull status did not automatically change, although the original vote was 6-1. The record was re-evaluated and voted on again, and fared even worse than before, with 4 votes not to "accept." Here is the 1999 annual report:
Personally, although I have done quite a few winter waterfowl counts along this very stretch of the river, I have never seen a Rock Dove (pigeon) out on the river with gulls and ducks. Less unusual would be a white Rock Dove, but I can't say I have seen too many in my 30+ years of urban birding, and none with black legs as described (Rock Doves nearly always have pink legs and feet).
When Ivory Gulls are seen in the U.S. or southern Canada, it is not uncommon for several birds to be present, or for one bird to range widely throughout a region over the season*. On 1 January 1949, less than two weeks before the Detroit River sighting, an Ivory Gull was reported from Lake Michigan's Waukegan Harbor. The Illinois records committee report, published in 2003:
And just prior to that, from 28-31 December 1948, an immature Ivory Gull was present in at Port Burwell on Lake Erie, Ontario.
To my knowledge, the Detroit River Ivory Gull is the first report of this species in Michigan, and the only record from Wayne County.
*This winter, an Ivory Gull was seen on 29 December 2016 outside Columbus, Ohio, and another on 3 March 2017 in Colchester, Ontario; some people speculated the latter bird was the same one that showed up in Flint.
Friday, January 6, 2017
Dearborn portion of the Detroit River Christmas Bird Count 2017
The Detroit River Michigan-Ontario Christmas Bird Count was held, as it
is each year, on January 1. This was the 40th year for the count, which
is centered at I-94 and Warren Ave, and the 23rd year that RRBO has coordinated the field work in the city of Dearborn.
After a warm and late fall, the area experienced both a couple of very cold spells and one deep snow. All was gone by count day, however, and the weather was the most pleasant January 1 we have experienced in a long time. Flowing water was open, so waterfowl was not only not concentrated, but apparently largely elsewhere. The Rouge River at the Ford Rouge complex usually has a decent variety of diving ducks, they were absent for the second winter in a row. The complex is also an unusual but annual wintering spot for Black-crowned Night-herons. Only one was in the usual spot, with eight others along the river's open waters instead. This was a low number, as there are usually around 20 or so in this location.
As is often the case, gulls were the story at the Rouge Plant. This year, a first winter Iceland Gull was a first for the Dearborn portion of the count, and a first record for Dearborn. This brings the Dearborn bird checklist to 264 species. The bird was found by the crew that has permission to bird in the plant: Mike O'Leary, Jim Fowler, and Dave Washington. Photos below by Mike and Dave.
Campus was well covered, and a Pileated Woodpecker that has been present in the area since fall was located -- not only the first recorded on the Dearborn portion of the count, but the first for the entire 40-year history of the Detroit River count.
Counters were prevented from covering the south end of campus controlled by Fairlane Estate, so a large portion of the open river and riparian areas were not covered.
A number of the Ford sunflower fields were either mowed or being used for construction. Two others were briefly covered. This is the first year Cooper’s Hawk was missed on count day in 21 years, and the first year since 2010 Peregrine was missed; lack of habitat for prey birds around the Ford headquarters was no doubt a factor.
The number of American Robins was the lowest since 1999. Eight American Crows was a comeback of sorts, as they were missed the last two years; there have been more than 8 crows only once in the last 13 years.
The most interesting non-bird observation of the day were the trees along the Rouge River across from the Dearborn Country Club that were being girdled by beavers. The largest tree was about 12 inches in diameter.
We
ended the day with 41 bird species. The two new additions bring the cumulative total for the Dearborn portion of the count to 90 species.
After a warm and late fall, the area experienced both a couple of very cold spells and one deep snow. All was gone by count day, however, and the weather was the most pleasant January 1 we have experienced in a long time. Flowing water was open, so waterfowl was not only not concentrated, but apparently largely elsewhere. The Rouge River at the Ford Rouge complex usually has a decent variety of diving ducks, they were absent for the second winter in a row. The complex is also an unusual but annual wintering spot for Black-crowned Night-herons. Only one was in the usual spot, with eight others along the river's open waters instead. This was a low number, as there are usually around 20 or so in this location.
As is often the case, gulls were the story at the Rouge Plant. This year, a first winter Iceland Gull was a first for the Dearborn portion of the count, and a first record for Dearborn. This brings the Dearborn bird checklist to 264 species. The bird was found by the crew that has permission to bird in the plant: Mike O'Leary, Jim Fowler, and Dave Washington. Photos below by Mike and Dave.
Campus was well covered, and a Pileated Woodpecker that has been present in the area since fall was located -- not only the first recorded on the Dearborn portion of the count, but the first for the entire 40-year history of the Detroit River count.
Counters were prevented from covering the south end of campus controlled by Fairlane Estate, so a large portion of the open river and riparian areas were not covered.
A number of the Ford sunflower fields were either mowed or being used for construction. Two others were briefly covered. This is the first year Cooper’s Hawk was missed on count day in 21 years, and the first year since 2010 Peregrine was missed; lack of habitat for prey birds around the Ford headquarters was no doubt a factor.
The number of American Robins was the lowest since 1999. Eight American Crows was a comeback of sorts, as they were missed the last two years; there have been more than 8 crows only once in the last 13 years.
The most interesting non-bird observation of the day were the trees along the Rouge River across from the Dearborn Country Club that were being girdled by beavers. The largest tree was about 12 inches in diameter.
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| Older work. |
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| Recent munching. |
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| Very fresh tooth marks. |
Monday, February 29, 2016
Winter Bird Population Survey 2015-2016
The 24th year of RRBO's Winter Bird Population Survey
has been completed.
After two brutally cold winters, this one was much milder, less snowy, and generally more pleasant. Surveys were conducted on 13 days (one day fewer than the mean) and a little over 20 hours total (lower than the mean of 28). Access restrictions continued this year. I was unable to survey anywhere along the Rouge River from Fair Lane Estate south due to it being fenced off for continued riverbank restoration. Thus, no Belted Kingfishers or Rock Pigeons were recorded (for the latter, the first time in 24 years). Only a few herons, and not many waterfowl were counted. Heavy construction activity continued along Fair Lane Drive for the new science building, impacting bird activity along eastern edge of survey area.
Nonetheless, the 38 species tallied was right on average. Two new species for the survey were recorded: Sandhill Crane and Wood Duck. These early migrants came at the very end of the season following a very warm weekend with southerly winds. These bring the cumulative total for the survey to 77 species.
Other uncommon species included a Bald Eagle; this adult bird was first seen in late December and continued to be spotted throughout the count period along the Rouge River (mostly on the south end of campus and along the concrete channel) but was only seen on one survey day. Although eagles are almost annual here, it was only the second time one has been recorded on this survey. A (singing!) Fox Sparrow early in the survey period was the third recorded for the survey. One or two American Crows were found on 4 survey dates. These birds were at the far north end of the campus.
At the other end of the spectrum, 7 species were found on all 13 survey days. In descending order of abundance they were: House Sparrow, House Finch, Northern Cardinal, Blue Jay, Black-capped Chickadee, Downy Woodpecker, and White-breasted Nuthatch -- all feeder birds. House Finches and House Sparrows were recorded in numbers well above average. For House Finches it was a record year, with a 127% increase from average.
Once again fruit-eating birds were largely absent. Three Cedar Waxwings on the first survey day were the only ones of the season. No Hermit Thrushes or Yellow-rumped Warblers were recorded. American Robins were counted, when present, in single digits most of the period. Last year robins were generally scarce on regional winter bird counts. This winter numbers of robins reported to eBird in southeast Michigan were much higher than last winter. This suggests that the removal of fruit-bearing non-native trees and shrubs that is being undertaken by the university the past few years has had an impact on these numbers. This seems to be substantiated by data recorded this year showing that only 30% of the robins recorded were in areas where this type of vegetation removal had taken place.
For all the numbers from this year you can visit the RRBO web site. The page includes past counts and the history and methodology of the survey.
After two brutally cold winters, this one was much milder, less snowy, and generally more pleasant. Surveys were conducted on 13 days (one day fewer than the mean) and a little over 20 hours total (lower than the mean of 28). Access restrictions continued this year. I was unable to survey anywhere along the Rouge River from Fair Lane Estate south due to it being fenced off for continued riverbank restoration. Thus, no Belted Kingfishers or Rock Pigeons were recorded (for the latter, the first time in 24 years). Only a few herons, and not many waterfowl were counted. Heavy construction activity continued along Fair Lane Drive for the new science building, impacting bird activity along eastern edge of survey area.
Nonetheless, the 38 species tallied was right on average. Two new species for the survey were recorded: Sandhill Crane and Wood Duck. These early migrants came at the very end of the season following a very warm weekend with southerly winds. These bring the cumulative total for the survey to 77 species.
Other uncommon species included a Bald Eagle; this adult bird was first seen in late December and continued to be spotted throughout the count period along the Rouge River (mostly on the south end of campus and along the concrete channel) but was only seen on one survey day. Although eagles are almost annual here, it was only the second time one has been recorded on this survey. A (singing!) Fox Sparrow early in the survey period was the third recorded for the survey. One or two American Crows were found on 4 survey dates. These birds were at the far north end of the campus.
At the other end of the spectrum, 7 species were found on all 13 survey days. In descending order of abundance they were: House Sparrow, House Finch, Northern Cardinal, Blue Jay, Black-capped Chickadee, Downy Woodpecker, and White-breasted Nuthatch -- all feeder birds. House Finches and House Sparrows were recorded in numbers well above average. For House Finches it was a record year, with a 127% increase from average.
Once again fruit-eating birds were largely absent. Three Cedar Waxwings on the first survey day were the only ones of the season. No Hermit Thrushes or Yellow-rumped Warblers were recorded. American Robins were counted, when present, in single digits most of the period. Last year robins were generally scarce on regional winter bird counts. This winter numbers of robins reported to eBird in southeast Michigan were much higher than last winter. This suggests that the removal of fruit-bearing non-native trees and shrubs that is being undertaken by the university the past few years has had an impact on these numbers. This seems to be substantiated by data recorded this year showing that only 30% of the robins recorded were in areas where this type of vegetation removal had taken place.
For all the numbers from this year you can visit the RRBO web site. The page includes past counts and the history and methodology of the survey.
Tuesday, January 12, 2016
Dearborn portion of Detroit River CBC, 2016
The Detroit River Michigan-Ontario Christmas Bird Count was held, as it
is each year, on January 1. This was the 38th year for the count, which
is centered at I-94 and Warren Ave, and the 22nd year that RRBO has coordinated the field work in the city of Dearborn.
After a record warm December, the new year came in cold (27-35F), breezy, and with snow flurries all day long. Water was still open, so waterfowl was not only not concentrated, but apparently largely elsewhere. The Rouge River at the Ford Rouge complex usually has a decent variety of diving ducks, but not this year. However, there were two Lesser Black-backed Gulls there; one there last year was the first on the count. Seven Great Black-backed Gulls were also present. This is a pretty average number now for a species that used to be rare in the Great Lakes. The complex is also an unusual but annual wintering spot for Black-crowned Night-herons. There were 22 counted this year, a little above the average of 19.2 for the previous 10 years. Peregrine Falcons have become nearly annual on the Dearborn portion of this count, and this year's was found at the complex as well.
After some issues the last couple of years, personnel was re-jiggered to make sure the UM-D campus habitat was well covered. The snow and wind made small birds hard to find, and in general nothing notable was found. The west side of the river across from campus was also thoroughly searched, and you can read about that section with some great photos of a hybrid Mallard x American Black Duck and robins eating privet at Into the Woods and Elsewhere.
A personal issue sidelined one participant, and left most sunflower/wildflower fields uncounted and some other routes in the city uncovered. Only one major field had standing sunflowers, though, the one in front of Ford World Headquarters at Michigan Avenue and Mercury. It got a quick once-over, and the count’s third Merlin was found there.
Pine Siskins have only been recorded on four counts, so 14 at a west Dearborn feeder was a good find. An adult Bald Eagle has been seen around the river several times, but didn't show up on count day. It was found on January 2 for a "count week" species. Red-breasted Nuthatches have been very scarce the last couple of winters, but one has been seen regularly in the Springwells Park neighborhood. Unfortunately, it was last seen sometime around Christmas.
Everyone familiar with this count and our winter bird surveys knows that Dearborn has not seen its American Crow population recover since it was decimated by West Nile Virus -- my most recent summary is here. Last year it finally happened: no crows for the first time in the history of the count. This year there were also no crows counted.
We ended the day with 37 pecies, which is a record low. No new species this year keeps the cumulative species count for the Dearborn portion of this CBC at 88.
The complete results of the Dearborn portion of the Detroit River CBC can be found at the RRBO web site, which includes historical results.
You can read an analysis of the first 25 years of the overall count in this paper:
Craves, J. A., and J. A. Fowler, Jr. 2003. Twenty-five years of the Detroit River Michigan-Ontario Christmas Bird Count (pdf). Ontario Birds 21:109-128.
After a record warm December, the new year came in cold (27-35F), breezy, and with snow flurries all day long. Water was still open, so waterfowl was not only not concentrated, but apparently largely elsewhere. The Rouge River at the Ford Rouge complex usually has a decent variety of diving ducks, but not this year. However, there were two Lesser Black-backed Gulls there; one there last year was the first on the count. Seven Great Black-backed Gulls were also present. This is a pretty average number now for a species that used to be rare in the Great Lakes. The complex is also an unusual but annual wintering spot for Black-crowned Night-herons. There were 22 counted this year, a little above the average of 19.2 for the previous 10 years. Peregrine Falcons have become nearly annual on the Dearborn portion of this count, and this year's was found at the complex as well.
After some issues the last couple of years, personnel was re-jiggered to make sure the UM-D campus habitat was well covered. The snow and wind made small birds hard to find, and in general nothing notable was found. The west side of the river across from campus was also thoroughly searched, and you can read about that section with some great photos of a hybrid Mallard x American Black Duck and robins eating privet at Into the Woods and Elsewhere.
A personal issue sidelined one participant, and left most sunflower/wildflower fields uncounted and some other routes in the city uncovered. Only one major field had standing sunflowers, though, the one in front of Ford World Headquarters at Michigan Avenue and Mercury. It got a quick once-over, and the count’s third Merlin was found there.
 |
| Merlin. Photo copyrighted, no use without permission. |
Pine Siskins have only been recorded on four counts, so 14 at a west Dearborn feeder was a good find. An adult Bald Eagle has been seen around the river several times, but didn't show up on count day. It was found on January 2 for a "count week" species. Red-breasted Nuthatches have been very scarce the last couple of winters, but one has been seen regularly in the Springwells Park neighborhood. Unfortunately, it was last seen sometime around Christmas.
Everyone familiar with this count and our winter bird surveys knows that Dearborn has not seen its American Crow population recover since it was decimated by West Nile Virus -- my most recent summary is here. Last year it finally happened: no crows for the first time in the history of the count. This year there were also no crows counted.
We ended the day with 37 pecies, which is a record low. No new species this year keeps the cumulative species count for the Dearborn portion of this CBC at 88.
The complete results of the Dearborn portion of the Detroit River CBC can be found at the RRBO web site, which includes historical results.
You can read an analysis of the first 25 years of the overall count in this paper:
Craves, J. A., and J. A. Fowler, Jr. 2003. Twenty-five years of the Detroit River Michigan-Ontario Christmas Bird Count (pdf). Ontario Birds 21:109-128.
Friday, December 18, 2015
Seed-a-palooza
Time for an update on the seed and diet study -- one in which may explain why blog posts have been so infrequent over the past year.
Recap of RRBO's research trajectory
When RRBO was founded in 1992, there was very little research being done on how birds used urban natural areas. Our first task was to establish solid baseline data on the species, relative abundance, and seasonal distribution of birds using the UM-Dearborn campus utilizing historical data, standardized regular surveys, and bird banding. This has resulted in a variety of publications, including a book, documenting the 261 species of birds found in the city of Dearborn, mostly on campus.
Once we understood that many birds used the area, our next question was: How? Were migratory birds that stopped here able to find the resources that would enable them to continue their migratory journey? Based on our banding data, we looked at 15 years of recaptures of thrushes during fall migration, and found that all three species for which we had sufficient data -- Gray-cheeked, Swainson's, and Hermit Thrushes -- did gain enough mass to make the next leg of their migratory flight. This research was published in 2009 in The Wilson Journal of Ornithology.
That led us to another question: What were these birds eating that helped them gain weight? Fortunately, there is a reliable and low-tech way to find out: identify the seeds in their poop. Over 300 samples consisting of over 1200 seeds were analyzed from Hermit and Swainson's Thrushes, and a paper summarizing the results is in progress. The majority of samples were from two non-native plant species, Amur Honeysuckle and Common Buckthorn. This was a little surprising, because these species were said to have little nutritional value to birds.
Every "answer" leads to more questions!
Current research
Our thrush work led me to begin working on the following...
Were fruits being eaten in proportion to their abundance in the landscape?
Last year I finished up censusing fruit in a large plot to provide us with a sense of the rank abundance of all the ripe fruit available to birds to eat throughout the fall season. The end of this post describes that work.
Were there some intrinsic characteristics (size, number of seeds, etc.) of the fruits that made some more apt to be consumed than others?
This fall and winter I will be finishing up the fruit morphology work, which I first described in detail in this post. I will have detailed data on many physical characteristics of the fruit of 40 species of fall-fruiting plants, based on measurements of over 6500 fruits and over 9000 seeds (so far!). I'll be preparing a paper on this data for The Michigan Botanist.
Were migratory thrushes eating non-native fruits because resident birds had already eaten the "better" native fruits before the thrushes arrived?
In 2009, we started collecting fecal samples from all bird other species we banded. Two things became immediately clear. First, other birds began eating honeysuckles and buckthorn as soon as they became ripe, even when native species like pokeweed and dogwoods were available. Second, we could collect A LOT of samples from American Robins.
Robins have been RRBO's most commonly banded species, although they are poor subjects for mass gain studies. We rarely recapture them and we cannot distinguish which nested in the area and which were migrants (thus making it impossible to estimate stopover duration and obscuring mass gain patterns).
Since we don't need to rely on mass gain data, we don't need to capture robins and can use "seed traps" to collect robin samples. Often, seed trap arrays are plastic trays with drainage and screen tops placed throughout an area frequented by birds. This is a costly method in an area like ours where field equipment is frequently vandalized. Fortunately, robins have the habit of gathering at drinking and bath sites, during which time they nearly always poop. We began collecting samples from robins when we were able to observe a flock around puddles or foraging in a specific area within our study plot. When a small retention pond was constructed right outside the banding lab, we set out boards along the margins -- these made excellent seed traps! In 2013, we also began collecting samples at a Washtenaw County site which has more native fruiting plants and fewer non-natives (especially honeysuckle) to use as a comparison, using similar methods.
This fall, 949 samples were collected from robins, bringing the 2009-2015 fall total of samples to 2207 consisting of 16931 seeds, of which only one was unidentified! And why stop in fall? Robins are here nearly year-round, so we have continued to collect in winter, and have 350 samples (2252 seeds). At the Washtenaw County site the total number of robin samples is 1135 (6327 seeds) for fall and 792 (4515 seeds) for winter just over the past two years. Summer samples are being collected as well, although fewer plants fruit in summer. Samples are also collected from all species banded at the Washtenaw site.
So far, altogether, from both sites for all species throughout the year, RRBO has collected and compiled data on over 5300 samples consisting of over 35000 seeds.
This very robust data set will show us what fruits robins eat (and therefore disperse in the landscape) throughout the year in both an urban and more rural setting.
Because fruit crops vary from year to year, I want to continue the collection (especially in winter) for at least another year. I'll have to draw the line at some point in order to dedicate some large blocks of time dedicated to data analysis, rather than data collection!
Recap of RRBO's research trajectory
When RRBO was founded in 1992, there was very little research being done on how birds used urban natural areas. Our first task was to establish solid baseline data on the species, relative abundance, and seasonal distribution of birds using the UM-Dearborn campus utilizing historical data, standardized regular surveys, and bird banding. This has resulted in a variety of publications, including a book, documenting the 261 species of birds found in the city of Dearborn, mostly on campus.
Once we understood that many birds used the area, our next question was: How? Were migratory birds that stopped here able to find the resources that would enable them to continue their migratory journey? Based on our banding data, we looked at 15 years of recaptures of thrushes during fall migration, and found that all three species for which we had sufficient data -- Gray-cheeked, Swainson's, and Hermit Thrushes -- did gain enough mass to make the next leg of their migratory flight. This research was published in 2009 in The Wilson Journal of Ornithology.
That led us to another question: What were these birds eating that helped them gain weight? Fortunately, there is a reliable and low-tech way to find out: identify the seeds in their poop. Over 300 samples consisting of over 1200 seeds were analyzed from Hermit and Swainson's Thrushes, and a paper summarizing the results is in progress. The majority of samples were from two non-native plant species, Amur Honeysuckle and Common Buckthorn. This was a little surprising, because these species were said to have little nutritional value to birds.
Every "answer" leads to more questions!
Current research
Our thrush work led me to begin working on the following...
Were fruits being eaten in proportion to their abundance in the landscape?
Last year I finished up censusing fruit in a large plot to provide us with a sense of the rank abundance of all the ripe fruit available to birds to eat throughout the fall season. The end of this post describes that work.
Were there some intrinsic characteristics (size, number of seeds, etc.) of the fruits that made some more apt to be consumed than others?
This fall and winter I will be finishing up the fruit morphology work, which I first described in detail in this post. I will have detailed data on many physical characteristics of the fruit of 40 species of fall-fruiting plants, based on measurements of over 6500 fruits and over 9000 seeds (so far!). I'll be preparing a paper on this data for The Michigan Botanist.
Were migratory thrushes eating non-native fruits because resident birds had already eaten the "better" native fruits before the thrushes arrived?
In 2009, we started collecting fecal samples from all bird other species we banded. Two things became immediately clear. First, other birds began eating honeysuckles and buckthorn as soon as they became ripe, even when native species like pokeweed and dogwoods were available. Second, we could collect A LOT of samples from American Robins.
Robins have been RRBO's most commonly banded species, although they are poor subjects for mass gain studies. We rarely recapture them and we cannot distinguish which nested in the area and which were migrants (thus making it impossible to estimate stopover duration and obscuring mass gain patterns).
Since we don't need to rely on mass gain data, we don't need to capture robins and can use "seed traps" to collect robin samples. Often, seed trap arrays are plastic trays with drainage and screen tops placed throughout an area frequented by birds. This is a costly method in an area like ours where field equipment is frequently vandalized. Fortunately, robins have the habit of gathering at drinking and bath sites, during which time they nearly always poop. We began collecting samples from robins when we were able to observe a flock around puddles or foraging in a specific area within our study plot. When a small retention pond was constructed right outside the banding lab, we set out boards along the margins -- these made excellent seed traps! In 2013, we also began collecting samples at a Washtenaw County site which has more native fruiting plants and fewer non-natives (especially honeysuckle) to use as a comparison, using similar methods.
This fall, 949 samples were collected from robins, bringing the 2009-2015 fall total of samples to 2207 consisting of 16931 seeds, of which only one was unidentified! And why stop in fall? Robins are here nearly year-round, so we have continued to collect in winter, and have 350 samples (2252 seeds). At the Washtenaw County site the total number of robin samples is 1135 (6327 seeds) for fall and 792 (4515 seeds) for winter just over the past two years. Summer samples are being collected as well, although fewer plants fruit in summer. Samples are also collected from all species banded at the Washtenaw site.
So far, altogether, from both sites for all species throughout the year, RRBO has collected and compiled data on over 5300 samples consisting of over 35000 seeds.
This very robust data set will show us what fruits robins eat (and therefore disperse in the landscape) throughout the year in both an urban and more rural setting.
Because fruit crops vary from year to year, I want to continue the collection (especially in winter) for at least another year. I'll have to draw the line at some point in order to dedicate some large blocks of time dedicated to data analysis, rather than data collection!
Monday, October 19, 2015
Introducing Craves’s Giant Barn Owl!
I recently received a great honor: a new (albeit extinct) species of owl was named after me. Craves’s Giant Barn Owl (Tyto cravesae) was recently described based on fossils discovered in Cuba by my great friend William Suárez. The bird was described in a recent paper published in the journal Zootaxa, Systematics and distribution of the giant fossil barn owls of the West Indies (Aves: Strigiformes: Tytonidae) by William, formerly a curator of the National Museum of Natural History and now living in the U.S., and Storrs L. Olson of the Smithsonian Institution.
The bones of this owl were discovered in a cave complex in Cuba by William in 1998, and subsequently in several other locations in Cuba. The paper reviews and revises previously described species, with two of those being synonymized with two others. Thus Tyto cravesae becomes the fourth extinct giant barn owl described from the West Indies.
These owls were all larger than Tyto alba, the common Barn Owl found across much of the world today, including in North America. Based on the bones found, Craves's Giant Barn Owl was likely somewhat larger than a Great Horned Owl. There were also even larger prehistoric owls in Cuba in the genus Ornimegalonyx, estimated to be a meter or more tall!
The cave deposits date from sometime in the late Pleistocene (the epoch ranging from 2.5 million to around 12,000 years ago), and include the bones of prey items. Craves's Giant Barn Owl fed on large rodents and small mammals. The lack of other predators on mammals besides giant birds in the West Indies is the main reason these owls evolved into such large forms. "My" owl probably often preyed upon hutias, a group of rodents endemic to the Caribbean region; one species identified with the Tyto cravesae bones was that of the Cuban or Desmarest's Hutia (Capromys pilorides). The giant Antillean owls probably became extinct due to the loss of their prey species.
I got to know William during several U.S. licensed trips to Cuba in the early 2000s in which I assisted with and lead bird surveys throughout the island. William is a leading authority on Caribbean birds and mammals, both living and extinct. He has written or co-authored many papers as well as a book, and described and named several other new genera and species of birds. Over the years, we kept in continuous touch both as friends and colleagues.
In the paper describing Tyto cravesae, the section describing the naming of the species states: "After Julie Craves, of the University of Michigan-Dearborn for her dedication to avian conservation and her boundless appreciation of Cuban friends and birds."
No matter what he
has encountered, William has persevered with remarkable optimism and
good humor. His strength and accomplishments have been a continual
source of inspiration to me. I am incredibly honored that he chose to name this new species of owl after me, when the true honor has been mine, simply having the opportunity to be his friend.
Read more at the BirdWatching Magazine blog, where William and I responded to questions from editor Chuck Hagner. In 2002, I also wrote an article for the magazine, The Birds of Cuba. In 2003, colleague Kim Hall and I published a paper on some of the survey's findings in the Journal of Caribbean Ornithology, Notable bird sightings from Cuba, winters 2002 and 2003 (pdf).
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| An artist's rendering of Ornimegalonyx at the Museo Nacional de Historia Natural de Cuba. Even bigger than Tyto cravesae! Photo by Darrin O'Brien. |
These owls were all larger than Tyto alba, the common Barn Owl found across much of the world today, including in North America. Based on the bones found, Craves's Giant Barn Owl was likely somewhat larger than a Great Horned Owl. There were also even larger prehistoric owls in Cuba in the genus Ornimegalonyx, estimated to be a meter or more tall!
The cave deposits date from sometime in the late Pleistocene (the epoch ranging from 2.5 million to around 12,000 years ago), and include the bones of prey items. Craves's Giant Barn Owl fed on large rodents and small mammals. The lack of other predators on mammals besides giant birds in the West Indies is the main reason these owls evolved into such large forms. "My" owl probably often preyed upon hutias, a group of rodents endemic to the Caribbean region; one species identified with the Tyto cravesae bones was that of the Cuban or Desmarest's Hutia (Capromys pilorides). The giant Antillean owls probably became extinct due to the loss of their prey species.
I got to know William during several U.S. licensed trips to Cuba in the early 2000s in which I assisted with and lead bird surveys throughout the island. William is a leading authority on Caribbean birds and mammals, both living and extinct. He has written or co-authored many papers as well as a book, and described and named several other new genera and species of birds. Over the years, we kept in continuous touch both as friends and colleagues.
In the paper describing Tyto cravesae, the section describing the naming of the species states: "After Julie Craves, of the University of Michigan-Dearborn for her dedication to avian conservation and her boundless appreciation of Cuban friends and birds."
No matter what he
has encountered, William has persevered with remarkable optimism and
good humor. His strength and accomplishments have been a continual
source of inspiration to me. I am incredibly honored that he chose to name this new species of owl after me, when the true honor has been mine, simply having the opportunity to be his friend. |
| Julie Craves and William Suárez at the Big House, August 2014. |
Monday, October 12, 2015
Yellow Rail - new Dearborn species
Another new species has been added to the Dearborn checklist. I received, through a chain of 6 people, a clear photo of a Yellow Rail
at the Ford Rouge Plant from October 8. It was at a building near the Dearborn Truck
Plant. There is wetland/pond habitat at the visitor center of the plant,
adjacent to the truck plant that the bird may have been attracted to. I
do not have permission to post the photo, but there is no doubt of the
identity of the bird.
I have no information how long/if the bird remained, but there is no public access to most of this facility. The photo showed the bird near a building. This could indicate it was injured, but I have heard of rails, including Yellow Rails, showing up in unusual locations like this during migration. Yellow Rails often try to flee by running and hiding rather than flying, yet may appear so tame as to emerge from marsh vegetation at an observer's feet. Thus, a good photo of an ambulatory rail doesn't necessarily indicate that the bird needed "rescuing."
Yellow Rails are secretive, marsh-dwelling birds that are hard to find even at known breeding locations, such as Seney National Wildlife Refuge in the Upper Peninsula. The species is listed as State Threatened in Michigan.
I have no information how long/if the bird remained, but there is no public access to most of this facility. The photo showed the bird near a building. This could indicate it was injured, but I have heard of rails, including Yellow Rails, showing up in unusual locations like this during migration. Yellow Rails often try to flee by running and hiding rather than flying, yet may appear so tame as to emerge from marsh vegetation at an observer's feet. Thus, a good photo of an ambulatory rail doesn't necessarily indicate that the bird needed "rescuing."
Yellow Rails are secretive, marsh-dwelling birds that are hard to find even at known breeding locations, such as Seney National Wildlife Refuge in the Upper Peninsula. The species is listed as State Threatened in Michigan.
Wednesday, July 8, 2015
Peregrine Falcons nesting in Dearborn
[Update: The jury is still out on the band number and identity. Barb Baldinger writes: "We
clearly saw 6/M, but want a better look. It could be 66/M and we only
saw the second 6, the space and first 6 in the way the numbers are
repeated. If that is the case, he is one of ours, Iggy from UD Mercy,
Detroit, hatched in 2011."]
Dearborn regularly hosts Peregrine Falcons, mostly in winter. The most "famous" of these was a Kentucky-born female named "Ember" who hung around in 2010. We knew her history based on the color and alpha-numeric codes on her leg bands.
This site probably has the best explanation on how to "read" Peregrine leg bands. If one is able to get a clear look at the bands and is in the 13-state, 2-province (ND, MN, WI, MI, SD, NE, IA, IL, IN, OH, KS, MO, KY, SE MB, and NW ON) midwest region, the Midwest Peregrine Society's database can be searched for more information.
A favorite location for falcons around here are the Parklane Towers on the north side of Hubbard east of the Southfield Freeway. The tall concrete buildings must look like cliffs, and there is ample hunting in the planted fields, urban areas, and the concrete channel of the Rouge River nearby. In 2013, a pair of Peregrines were present at the towers. At least one was banded, but the bands could not be read. They apparently raised at least one chick.
Last year, a pair returned, but left again in May. One returned in the summer, for a few days but left again.
Two Peregrines were seen over the winter of 2014-2015, and by April seemed to be tending a nest on the roof of one of the towers. Last month, a juvenile bird was seen by the southeast Michigan Peregrine monitors, and the bands of one of the adults was read: black-over-red, 6 over M-- or (b/r) 6/M in shorthand. However, this combo did not get a hit in the database. Grrr....
As a bander, I know that some bird bands have a "silent" leading zero (e.g., the physical band shows 932-12345, but all associated data is really assigned as 0932-12345). There IS a falcon in the database under (b/r) 06/M, a male hatched on 12 May 2012 in Vernon County, Wisconsin named "Drew." He was part of a brood from two unbanded Peregrines nesting at the the Dairyland Power Cooperative's Genoa generating station, on the Mississippi River just south of La Crosse (where my husband grew up). The company has had a nest site 375 feet up on a smokestack at the plant since 1997 as part of a Peregrine restoration program.
Hopefully, Chris or Barb (the monitors) or an occupant of one of the buildings will get a better look or photo of the bands and we can confirm the identity.
I went by last week and found this interesting scene.
Perhaps I should have stuck around to see how that turned out!
Dearborn regularly hosts Peregrine Falcons, mostly in winter. The most "famous" of these was a Kentucky-born female named "Ember" who hung around in 2010. We knew her history based on the color and alpha-numeric codes on her leg bands.
This site probably has the best explanation on how to "read" Peregrine leg bands. If one is able to get a clear look at the bands and is in the 13-state, 2-province (ND, MN, WI, MI, SD, NE, IA, IL, IN, OH, KS, MO, KY, SE MB, and NW ON) midwest region, the Midwest Peregrine Society's database can be searched for more information.
A favorite location for falcons around here are the Parklane Towers on the north side of Hubbard east of the Southfield Freeway. The tall concrete buildings must look like cliffs, and there is ample hunting in the planted fields, urban areas, and the concrete channel of the Rouge River nearby. In 2013, a pair of Peregrines were present at the towers. At least one was banded, but the bands could not be read. They apparently raised at least one chick.
Last year, a pair returned, but left again in May. One returned in the summer, for a few days but left again.
Two Peregrines were seen over the winter of 2014-2015, and by April seemed to be tending a nest on the roof of one of the towers. Last month, a juvenile bird was seen by the southeast Michigan Peregrine monitors, and the bands of one of the adults was read: black-over-red, 6 over M-- or (b/r) 6/M in shorthand. However, this combo did not get a hit in the database. Grrr....
As a bander, I know that some bird bands have a "silent" leading zero (e.g., the physical band shows 932-12345, but all associated data is really assigned as 0932-12345). There IS a falcon in the database under (b/r) 06/M, a male hatched on 12 May 2012 in Vernon County, Wisconsin named "Drew." He was part of a brood from two unbanded Peregrines nesting at the the Dairyland Power Cooperative's Genoa generating station, on the Mississippi River just south of La Crosse (where my husband grew up). The company has had a nest site 375 feet up on a smokestack at the plant since 1997 as part of a Peregrine restoration program.
Hopefully, Chris or Barb (the monitors) or an occupant of one of the buildings will get a better look or photo of the bands and we can confirm the identity.
I went by last week and found this interesting scene.
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| An adult falcon was watching the window washers start down the opposite building. |
Wednesday, July 1, 2015
Grasshopper Sparrows nesting in Dearborn
[Update: As of late July, the sparrows are still present. The vegetation is high enough that it is not possible to tell if they are feeding young without going out into the field, so we are unlikely to confirm this. However, their presence on territory this long indicates they have likely nested. Here's a link to an article Oakwood posted about the sparrows.]
On 26 May, long-time RRBO volunteer and contributor Mike O'Leary found several singing Grasshopper Sparrows in the vacant lot at Rotunda and Southfield. This lot was once the site of some Ford Motor Company buildings, which were torn down around 2003. It is now managed by the Oakwood Physical Therapy & Wellness Center. Even after all these years, the footprint of the old buildings on the easterly portion of the property closest to the Southfield Freeway and service drive can be seen.
Up to four singing males continued at the site in June. Grasshopper Sparrows are considered a Species of Special Concern in Michigan, a status just below the legally-protected status of Threatened. In addition to a significant population decline statewide, surveys have shown that their numbers have decreased 4% annually in Michigan from 1996-2007. During the Michigan Breeding Bird Atlas period in 2002-2007, Grasshopper Sparrows were only confirmed nesting in one western township in Wayne County. While Grasshopper Sparrows probably nested in Dearborn at some point prior to 1900 or so, there have been only a handful of records of spring migrants since the 1970s, and just one summer record of one individual. These territorial birds represent the first likely nesting in the city in modern times.
Not all grasslands or fallow land is equal to the various species of grassland birds. Grasshopper Sparrows have a strong preference for habitat that is mostly grasses and forbs (herbaceous weeds) which are not densely distributed, interspersed with bare ground (up to 20%), and few or no shrubs. The portion of the site that once had buildings on it have numerous patches of bare ground or sparse vegetation on the former building footprint, and most of the sparrows have been found there.
Because it is adjacent to the freeway, the insect-like song of the Grasshopper Sparrows are very difficult to hear! The field is also full of dozens of nesting Savannah Sparrows, Red-winged Blackbirds, and Killdeer, among other species. They make quite a ruckus, but we believe there are still likely up to four singing male Grasshopper Sparrows and, due to their duration at the site and the persistence of the location of at least one of the males closest to the parking lot, they are likely nesting. Because we do not want to risk stepping on the ground nests of any sparrows or disturbance to any birds, we've restricted our regular surveys to the edge of the property after I made one thorough walk-through.
After I notified Oakwood of this special bird, they instantly stepped to the plate and made plans to postpone any mowing of the field until August, after any young should be fledged and independent.
We will be keeping an eye on the sparrows to see if we can catch them feeding young in the next few weeks. Many thanks to Oakwood for the stewardship of these special birds.
On 26 May, long-time RRBO volunteer and contributor Mike O'Leary found several singing Grasshopper Sparrows in the vacant lot at Rotunda and Southfield. This lot was once the site of some Ford Motor Company buildings, which were torn down around 2003. It is now managed by the Oakwood Physical Therapy & Wellness Center. Even after all these years, the footprint of the old buildings on the easterly portion of the property closest to the Southfield Freeway and service drive can be seen.
Up to four singing males continued at the site in June. Grasshopper Sparrows are considered a Species of Special Concern in Michigan, a status just below the legally-protected status of Threatened. In addition to a significant population decline statewide, surveys have shown that their numbers have decreased 4% annually in Michigan from 1996-2007. During the Michigan Breeding Bird Atlas period in 2002-2007, Grasshopper Sparrows were only confirmed nesting in one western township in Wayne County. While Grasshopper Sparrows probably nested in Dearborn at some point prior to 1900 or so, there have been only a handful of records of spring migrants since the 1970s, and just one summer record of one individual. These territorial birds represent the first likely nesting in the city in modern times.
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| Low grasses and taller forbs (mostly sweet clovers, Melilotus ssp., and fleabanes, Erigeron ssp.,) in the area favored by the sparrows. |
Not all grasslands or fallow land is equal to the various species of grassland birds. Grasshopper Sparrows have a strong preference for habitat that is mostly grasses and forbs (herbaceous weeds) which are not densely distributed, interspersed with bare ground (up to 20%), and few or no shrubs. The portion of the site that once had buildings on it have numerous patches of bare ground or sparse vegetation on the former building footprint, and most of the sparrows have been found there.
 |
| Patches of bare ground are required by Grasshopper Sparrows. |
We will be keeping an eye on the sparrows to see if we can catch them feeding young in the next few weeks. Many thanks to Oakwood for the stewardship of these special birds.
Thursday, March 5, 2015
Winter Bird Population Survey 2014-2015
The 23rd year of RRBO's Winter Bird Population Survey has been completed. December started out pleasantly but the survey season ended with a snowy and bitterly cold February. Weather aside, it was a fairly average year. The 14 survey days over the late December to late February period was typical. Surveys totaled about 23 hours, which is 6 hours below the 29 hours that are average, but represent the shortage that took place on our Christmas Bird Count day.
The 34 species tallied was a little below the 22-year average of 38, but can be partially explained by some habitat changes and restrictions. Access to the Rouge River behind Fair Lane Estate was greatly restricted due to being fenced off for riverbank restoration; vegetation along this area also removed. The river was frozen much of the period, and no waterfowl were counted after January 1. No Belted Kingfishers were recorded; they have only been completely missed on a few other counts.
Heavy construction activity along Fair Lane Drive also impacted bird activity along eastern edge of survey area. This construction will be continuing through summer, and likely also have an effect on spring surveys.
Eleven species were found on all 14 survey days. In descending order of abundance they were: House Sparrow, House Finch, Northern Cardinal, Blue Jay, Black-capped Chickadee, Dark-eyed Junco, Downy Woodpecker, White-breasted Nuthatch, Tufted Titmouse, Red-bellied Woodpecker, and Hairy Woodpecker -- all feeder birds.
Despite the availability of feeders, most sparrows were recorded in numbers well below average. Only a single Song Sparrow was recorded, while the previous season total average is 13. One or two American Tree Sparrows were recorded several times, but the previous season total average is 34. White-throated Sparrows have been common winter residents here, especially over the past decade. A total of 25 were counted this year, with an average per survey of 1.7, the lowest numbers since 2002. The previous 22-year means were 80 per season and 6 per survey; these averages since 2003 were 157 and 9. Juncos were also counted in below average numbers, although not as drastic. I'm not sure exactly what might have contributed to the depressed numbers of ground-feeding seed eaters, except that a lot of understory vegetation has been removed and perhaps there is less cover.
Fruit-eating birds were largely absent. No Cedar Waxwings, Hermit Thrushes, or Yellow-rumped Warblers were recorded. Most days there were no American Robins present, the maximum number on a survey day was 3. This represents the second lowest number of American Robins in 23 years. Fruit-eating species were generally scarce on local winter bird counts this winter, so it's hard to tell what impact the removal of fruit-bearing non-native trees and shrubs that was undertaken by the university may have had on these numbers.
The highlight was probably the Pine Siskins that were present in small numbers through mid-January. They moved on from here (and other places locally) and had not moved back through on their way north by the time the survey period ended. This was the only one of the "irruptive" species present on campus this winter.
All the numbers from this year are on the RRBO web site, along with past counts and the history and methodology of the survey.
The 34 species tallied was a little below the 22-year average of 38, but can be partially explained by some habitat changes and restrictions. Access to the Rouge River behind Fair Lane Estate was greatly restricted due to being fenced off for riverbank restoration; vegetation along this area also removed. The river was frozen much of the period, and no waterfowl were counted after January 1. No Belted Kingfishers were recorded; they have only been completely missed on a few other counts.
Heavy construction activity along Fair Lane Drive also impacted bird activity along eastern edge of survey area. This construction will be continuing through summer, and likely also have an effect on spring surveys.
Eleven species were found on all 14 survey days. In descending order of abundance they were: House Sparrow, House Finch, Northern Cardinal, Blue Jay, Black-capped Chickadee, Dark-eyed Junco, Downy Woodpecker, White-breasted Nuthatch, Tufted Titmouse, Red-bellied Woodpecker, and Hairy Woodpecker -- all feeder birds.
Despite the availability of feeders, most sparrows were recorded in numbers well below average. Only a single Song Sparrow was recorded, while the previous season total average is 13. One or two American Tree Sparrows were recorded several times, but the previous season total average is 34. White-throated Sparrows have been common winter residents here, especially over the past decade. A total of 25 were counted this year, with an average per survey of 1.7, the lowest numbers since 2002. The previous 22-year means were 80 per season and 6 per survey; these averages since 2003 were 157 and 9. Juncos were also counted in below average numbers, although not as drastic. I'm not sure exactly what might have contributed to the depressed numbers of ground-feeding seed eaters, except that a lot of understory vegetation has been removed and perhaps there is less cover.
Fruit-eating birds were largely absent. No Cedar Waxwings, Hermit Thrushes, or Yellow-rumped Warblers were recorded. Most days there were no American Robins present, the maximum number on a survey day was 3. This represents the second lowest number of American Robins in 23 years. Fruit-eating species were generally scarce on local winter bird counts this winter, so it's hard to tell what impact the removal of fruit-bearing non-native trees and shrubs that was undertaken by the university may have had on these numbers.
The highlight was probably the Pine Siskins that were present in small numbers through mid-January. They moved on from here (and other places locally) and had not moved back through on their way north by the time the survey period ended. This was the only one of the "irruptive" species present on campus this winter.
All the numbers from this year are on the RRBO web site, along with past counts and the history and methodology of the survey.
Monday, March 2, 2015
Dearborn adds another new species!
On 1 March 2015, Larry Urbanski found a Long-tailed Duck (Clangula hyemalis) in the Rouge River near the Ford Rouge Plant. There is a photo attached to his eBird checklist (sign in may be required for one or both links) and the bird appears to be a male.
Mike O'Leary and I attempted to locate the bird this morning, and found a Long-tailed Duck that appears to be a female, or at least doesn't look like the bird found yesterday. In the photo below, it's the bird on the left, next to a Red-breasted Merganser. I should be able to post some better photos later.
Long-tailed Duck is the 260th species on the Dearborn list.
Most of the Rouge River is still frozen solid. The areas in the Ford Rouge boat slip and adjacent waters stay open all year. Other waterfowl present included a couple hundred Common Mergansers, at least 24 Red-breasted Mergansers, Canvasbacks, a few Ruddy Ducks, Common Goldeneye, Redheads, and Greater Scaup. There were at least 20 Great Black-backed Gulls -- a species not recorded in Dearborn until 1987. Ten sort of miserable looking Great Blue Herons hugged the shoreline, as did 10 Black-crowned Night-herons. There is a small pond inside the plant next to the river that accepts warm-water discharge from one of the steel mill facilities, and a bunch of night-herons have wintered there for years.
Many thanks to Larry Urbanski for this great find.
Mike O'Leary and I attempted to locate the bird this morning, and found a Long-tailed Duck that appears to be a female, or at least doesn't look like the bird found yesterday. In the photo below, it's the bird on the left, next to a Red-breasted Merganser. I should be able to post some better photos later.
Long-tailed Duck is the 260th species on the Dearborn list.
Most of the Rouge River is still frozen solid. The areas in the Ford Rouge boat slip and adjacent waters stay open all year. Other waterfowl present included a couple hundred Common Mergansers, at least 24 Red-breasted Mergansers, Canvasbacks, a few Ruddy Ducks, Common Goldeneye, Redheads, and Greater Scaup. There were at least 20 Great Black-backed Gulls -- a species not recorded in Dearborn until 1987. Ten sort of miserable looking Great Blue Herons hugged the shoreline, as did 10 Black-crowned Night-herons. There is a small pond inside the plant next to the river that accepts warm-water discharge from one of the steel mill facilities, and a bunch of night-herons have wintered there for years.
Many thanks to Larry Urbanski for this great find.
Saturday, January 10, 2015
Dearborn portion of Detroit River CBC, 2015
The Detroit River Michigan-Ontario Christmas Bird Count was held, as it
is each year, on January 1. This was the 37th year for the count, which
is centered at I-94 and Warren Ave, and the 21st year that RRBO has coordinated the field work in the city of Dearborn.
The skies were fair, but the temperatures were cold and windy. This was the first real cold snap of winter after a very mild fall and December. It was cold enough to freeze up a lot of water, but as count day was only a few days into the cold snap, it had not really been cold enough to push a lot of regional waterfowl into the always ice-free areas in our count circle. For example, this was onlly the second year that Canvasback were not counted; in fact, Common Merganser was the only diving duck recorded this year.
Unfortunately, our two counters on campus had unexpected family obligations, resulting in the best remaining habitat in the circle being under-covered. We had the lowest number of party-hours in our history, and raw numbers of many species of common birds were record lows, but not really reflective of actual populations. For these species, the Winter Bird Population Survey will provide more accurate numbers.
The obvious highlight of the count was a Lesser Black-backed Gull, found at the Ford Rouge Plant by Jim Fowler, Mike O'Leary, and Dave Washington, and photographed by Dave.
Most years this team is able to get special permission to enter the complex and check out the open water in the boat slip and other areas not visible from outside the plant. This is the third Dearborn record for Lesser Black-backed Gull. The others were also at the plant, in January and December 2004. This brings the cumulative total for the Dearborn portion of the count to 88 species.
Fifteen Black-crowned Night-Herons were also in their usual wintering spot around an awful little pond in the plant (described in the 2011 post). Most Black-crowned Night-Herons move south for the winter, but a few stick around coastal spots in the Great Lakes.
The usually-productive Ford "sunflower" fields mostly lacked birds this year. The only one with sunflowers was at Ford World Headquarters, where we did have 48 Red-winged Blackbirds and many House Sparrows and American Goldfinch. However, all the sunflower heads were seedless. The fields at Hubbard and Southfield, usually the best, had been planted in hay and harvested. Not even weed seeds were evident.
One field had a few rows of sunflowers at the edge, but they were stripped and had no birds.
The skies were fair, but the temperatures were cold and windy. This was the first real cold snap of winter after a very mild fall and December. It was cold enough to freeze up a lot of water, but as count day was only a few days into the cold snap, it had not really been cold enough to push a lot of regional waterfowl into the always ice-free areas in our count circle. For example, this was onlly the second year that Canvasback were not counted; in fact, Common Merganser was the only diving duck recorded this year.
Unfortunately, our two counters on campus had unexpected family obligations, resulting in the best remaining habitat in the circle being under-covered. We had the lowest number of party-hours in our history, and raw numbers of many species of common birds were record lows, but not really reflective of actual populations. For these species, the Winter Bird Population Survey will provide more accurate numbers.
The obvious highlight of the count was a Lesser Black-backed Gull, found at the Ford Rouge Plant by Jim Fowler, Mike O'Leary, and Dave Washington, and photographed by Dave.
Most years this team is able to get special permission to enter the complex and check out the open water in the boat slip and other areas not visible from outside the plant. This is the third Dearborn record for Lesser Black-backed Gull. The others were also at the plant, in January and December 2004. This brings the cumulative total for the Dearborn portion of the count to 88 species.
Fifteen Black-crowned Night-Herons were also in their usual wintering spot around an awful little pond in the plant (described in the 2011 post). Most Black-crowned Night-Herons move south for the winter, but a few stick around coastal spots in the Great Lakes.
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| A view of the Rouge complex from the Dix Street bridge. Urban birding, anyone? |
The usually-productive Ford "sunflower" fields mostly lacked birds this year. The only one with sunflowers was at Ford World Headquarters, where we did have 48 Red-winged Blackbirds and many House Sparrows and American Goldfinch. However, all the sunflower heads were seedless. The fields at Hubbard and Southfield, usually the best, had been planted in hay and harvested. Not even weed seeds were evident.
One field had a few rows of sunflowers at the edge, but they were stripped and had no birds.
As usual, we had a Peregrine Falcon at the Ford World headquarters and vicinity, and another one heading north up the Rouge River behind Henry Ford College. There have been two reported off and on this winter in the area.
A male Ring-necked Pheasant that we flushed at Porath Park was the first on the count in 11 years. Porath (Kielb) Park is an 11-acre property
in a sparse residential area adjacent to railyards and an industrial
border of Detroit was once a clay mine for bricks. In the 1940s, fill
material from construction of I-94 was added. A federal brownfields
grant was used to clean up contamination (still no digging allowed,
according to warning signs) and it was turned into a park by the city in
2005. There are a variety of native plants there, but aside from a
trail that is mowed through it (although not this year, apparently), the park has not been maintained very
well and it's becoming weedy and overgrown. Still, we like to go take a look each year.
Everyone familiar with this count and our winter bird surveys knows that Dearborn has not seen its American Crow population recover since it was decimated by West Nile Virus -- my most recent summary is here. For this count, we've only counted 1-3 the last few years and this year it finally happened: no crows for the first time in the history of the count.
We ended the day with 38 pecies, which is a record low.
I've written summaries here at Net Results for the 2014, 2013, 2012, 2011, 2010, and 2009 counts.
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